Coal is a major source of energy in the United States. It is increasing in importance because of its abundance within the United States and because of the security and balance of payment problems which arise from reliance upon foreign oil.
Transport problems constitute one of the major difficulties in the use of coal. Many attempts have been made to solve this problem by preparing slurries of coal with carrier liquid and pumping said slurries from one point to another. The slurries so prepared, however, are often unpumpable at solids contents exceeding about 50 weight percent.